135821801 has 4 divisors (see below), whose sum is σ = 136891392. Its totient is φ = 134752212.

The previous prime is 135821779. The next prime is 135821809. The reversal of 135821801 is 108128531.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 135821801 - 2¹⁸ = 135559657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135821809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 534605 + ... + 534858.

It is an arithmetic number, because the mean of its divisors is an integer number (34222848).

Almost surely, 2^135821801 is an apocalyptic number.

It is an amenable number.

135821801 is a deficient number, since it is larger than the sum of its proper divisors (1069591).

135821801 is a wasteful number, since it uses less digits than its factorization.

135821801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1069590.

The product of its (nonzero) digits is 1920, while the sum is 29.

The square root of 135821801 is about 11654.2610662367. The cubic root of 135821801 is about 514.0316122109.

The spelling of 135821801 in words is "one hundred thirty-five million, eight hundred twenty-one thousand, eight hundred one".